Mil/aero group foresees shift to optical in 2012

SAN JOSE, Calif.  A leading standards group for military and aerospace markets will explore the feasibility of deploying in 2012 products with optical backplanes and system interconnects. The VITA Standards Organization plans to announce as early as next week a call for participation in a group to explore the issues.

The group's mission will be to define "the state of art in optical technologies, find out where the gaps are and work with silicon and systems vendors on how to partner to address those gaps so we can deploy in 2012 systems running up in the terabits," said Ray Alderman, executive director of VITA, a trade and standards group for the VMEbus widely used in mission-critical embedded systems.

"A lot of people are working on pieces of this problem, but we still have some mountains to climb," said Alderman. "I want to pull in the best minds in the industry together to find where the gaps are," he said.

Ray AldermanExecutive Director, VITA

Some engineers have already shown prototypes of 10 Gbit/second optical backplanes, Alderman said. In military and aerospace markets plug-and-play subsystems called line-replacement units (LRUs) are becoming increasingly popular and will require high-bandwidth interconnects, he added.

"I think we are at an inflection point where copper is not going to work in a lot of applications," Alderman said. "I've got a huge number of requests on my desk where apps are saturated at 10 Gbits—and all of them run 10 Gbits [over copper] for about three inches," he added, noting distance problems with high-speed copper interconnects.

Mainstream computer and communications vendors are also eyeing the transition from copper to optical technologies. However, their current work indicates the shift could still be a decade away.

The Optical Internetworking Forum, a group of computer and communications chip and systems vendors, recently held a public workshop to rally support for a draft standard which could drive copper and optical connections to 25G. Separately, Intel Corp. previewed in September work on a 10 Gbit/s optical system-to-system link called Light Peak it suggested could replace USB in ten years.

"I think the transition to optical will come much sooner in defense and aerospace," said Alderman. "People in my markets will pay $40,000 for a board that Cisco Systems has to sell for $1,500 because the telecom market is inundated with cost pressures," he said.

Mil/aero and other mission-critical embedded systems users will pay the high prices to get products with higher reliability rates and longer product lifetimes. "Other people can play all the games they want with copper, but if my systems fail people die," said Alderman.

It remains to be seen whether the new VITA effort will help drive the optical transition

In an annual report on the VMEbus market, Alderman noted the transition to optical has been three years away for the last 20 years. However, in an interview he also took credit for an initiative in cooling semiconductors that helped raise the state of the art an order of magnitude.

"It's up to the military applications segment to initiate this move away from copper and to a new generation of pure-optical architectures and technologies--and it's up to VITA and its members to lead the way," Alderman wrote in a blog late last year.

I think that reports of the death of copper are greatly exaggerated. As an engineer working to validate 10GBase-KR backplane channels running over 30 inches of copper PCB laminate and two board to backplane connectors, I am writing to report that copper backplanes are still alive and well in 2010. This copper versus optical debate reminds me a bit of the semiconductor's optical lithography versus e-beam lithography debate. Design engineers have this habit of overcoming one obstacle after another and continuing to squeeze more performance out of systems than anyone expected. The IEEE 802.3ba committee and the OIF-CEI-25 committees both working on 25Gbps copper channels haven't thrown in their towels yet either.